The present invention relates to a picture signal recording and reproducing apparatus which performs write-in and read-out of a plurality of hard discs used for, for example, a video server.
Previously, there has been a video server apparatus which supplies various types of pictures to individual users at the same time on the basis of the requirements of a large number of users. The video server apparatus is composed of a video stream server for performing transmission processing of a picture stream, and an application server for performing unreal time processing such as a navigation function or the like.
The application server on one side bears a central role in transmitting and receiving an information, and has a function of processing of a network protocol necessary for receiving and sending the information. Furthermore, the application server has an administrative data base, and controls applications, administrative information, customer information and the like in that administrative database.
The video stream server on the other side has a plurality of hard discs for storing data, a single hard disc for storing parity, an RAID (Redundant Arrays Inexpensive Discs) controller for performing the processing of write-in and read-out of the data for those hard discs, and a processor which performs conversion and rearrangement of the data and performs the data transmission. The video stream server is called an RAID apparatus.
In FIG. 1, an arrangement of a disc array apparatus composing a general RAID apparatus in the prior art is shown. The disc array apparatus has an input/output data control section (processor) 1 for converting an input data and a command into a SCSI (Small Computer System Interface) protocol and a SCSI command, a disc array controller (RAID controller) 2 which divides or integrates the data and controls write-in and read-out of the data, and a hard disc 3 composed of a HDD (Hard Disc Drive) 1,a HDD 2,a HDD 3,a HDD 4 . . . a HDD 7 for dispersedly storing the data and a HDD P capable of storing the parity. Here, the HDD P can be used for parity record only, but it can also be used for data record.
The action of the disc array apparatus like this will be described below. When recording a picture signal data, at the input/output data control section 1, for example, a supplied bit stream is divided into striping units of 1 word (8 bits). The reason why the bit stream is divided into 1 word like this is that the bit stream should be striped at the unit of 1 word corresponding to the picture element data since 1 picture element is composed of 8 bits and 8 bits correspond to 1 word. The divided striping units are accumulated in 7 pieces of data storing hard discs HDD 1, HDD 2, HDD 3, HDD 4 . . . HDD 7 by the disc array controller 2. The reason is that by dispersedly accumulating the units in 7 pieces of hard discs HDD 1, HDD 2, HDD 3, HDD 4 . . . HDD 7, the number of users who use the same picture at the same time, can be made to be larger. As the way of dispersed accumulation, there are a random layout and a striping layout. The random layout is suitable for the accumulation of a picture of the multi-rate, and the striping layout is characterized in that the operation efficiency of the disc is high. The segment data dispersedly accumulated by the striping layout are called striping units. Furthermore, by calculating the exclusive-OR(EXCLUSIVE-OR) of 7 pieces of bit data composed of respective head end bits of the bit stream of 7 words dispersedly accumulated in the 7 pieces of hard discs HDD 1, HDD 2, HDD 3, HDD 4 . . . HDD 7, a first parity bit P is produced. Similarly to the action to produce the first parity bit, by calculating the exclusive-OR of 7 pieces of bit data composed of the second bit of each word, a second parity bit P is produced. After that, continuously performing the same action, an eighth parity bit P is produced by calculating the exclusive-OR of 7 pieces of bit data composed of the eighth bit of each word, so that 8 bits of parity data are produced. The parity data 8 produced like this are recorded in the HDD P.
When reproducing the picture signal data, the disc array controller 2 reads out the striping units from the hard disc 3 according to an allocation table showing the data array relating to which hard disc accumulates the striping unit. Then, the input/output data control section 1 rearranges the read out striping units in the reproducing order, and absorbs the fluctuation and transmits them to a network. Furthermore, special reproducing functions such as a slow reproduction, a fast forward, a pause, a skip or the like are achieved by controlling the speed at which the disc array controller 2 reads out the striping units.
Furthermore, when writing in the data, the disc array controller 2 disperses the striping units to a plurality of hard discs, and on the other hand, gathers the dispersed striping units to one data stream when reading out the data.
In a disc array apparatus like this, 1 picture element or some continuous elements are recorded in each hard disc in order as a unit for every horizontal scanning line, and in this case, the upper and lower picture elements of the picture signal data and the same picture elements of the preceding and succeeding frames are recorded in the same hard disc. The recording action thereof will be described below.
Here, by using FIG. 2, the recording action in dispersedly recording the picture signal data into hard discs in this disc array apparatus, will be described. Here, the description will be given as for the picture element, wherein as mentioned above, 1 picture element is composed of 8 bits and 8 bits correspond to 1 word. FIG. 2 is a diagram of recording action in a case where a picture signal with A pieces of effective picture elements for every horizontal scanning line and M pieces of scanning lines for every 1 frame is dividedly recorded in 7 units of data hard discs. In FIG. 2, each square shows 1 picture element of each picture signal, and the numbers 1 to 7 in that show the numbers of the data hard discs (HDD 1 to HDD 7) in which the picture elements are recorded. Furthermore, the HDD P is a hard disc for recording parity. In FIG. 2, an effective picture element range 4 in the horizontal direction of the picture signal shown by A is composed of each of the picture elements of 1, 2, . . . , 6, 7, 1, 2, . . . , 6, 7 in the scanning line 1 in the vertical direction, and similarly, it is composed of each of the picture elements of 1, 2, . . . , 6, 7, 1, 2, 6, 7 in the scanning line 2 in the vertical direction, and it is composed of each of the picture elements of 1, 2, . . . , 6, 7, 1, 2, . . . , 6, 7 in the scanning line 3 in the vertical direction, . . . and it is composed of each of the picture elements of 1, 2, 6, 7, 1, 2, . . . , 6, 7 in the scanning line M in the vertical direction.
At this time, since the number A of effective picture elements becomes a multiple of 7 which is, the number of the data hard discs, the adjacent picture element data in the vertical direction are recorded in the 7 pieces of data storing hard discs HDD 1, HDD 2, HDD 3, HDD 4 . . . , HDD 7. That is, in the hard disc HDD 1, M pieces of 1, 1, 1, . . . , 1 are recorded as the record picture element 5, and in the hard disc HDD 2, M pieces of 2, 2, 2, . . . , 2 are recorded as the record picture element 6, and in the hard disc HDD 7, M pieces of 7, , 7, 7, . . . 7 are recorded as the record picture element 7.
In a disc array apparatus like this, apart from storing usual data in the 7 pieces of data storing hard discs HDD 1, HDD 2, HDD 3, HDD 4 . . . HDD 7, by providing a hard disc HDD P for writing in the parity, the data in which an error has occurred are arranged to be restored on the basis of the parity data 8 of the hard disc HDD P for parity when a trouble has occurred.
However, the conventional disc array apparatus like this has the following inconvenience: Since the upper and lower picture elements of the picture signal data and the same picture elements of the preceding and succeeding frames are recorded in the same hard disc, the picture element of [2] shown by the record picture element 6 becomes in error in cases where not less than 2 units of hard discs breakdown, for example, in a case where the data hard disc HDD 2 breaks down in FIG. 2, and consequently, the upper and lower picture elements of [2] of the picture signal data and the picture elements equal to [2] of the preceding and succeeding frames are also in error, so that the enormous data cannot be used for the interpolation of the picture element data, and the picture element data in the lateral direction and in the diagonal direction of the picture signal data can only be effective, and the picture element data in the lateral direction and in the diagonal direction can be used for the interpolation of the picture element data, but if the hard disc in which the picture element data in the lateral direction and in the diagonal direction are recorded, is also out of order, the interpolation should be performed by using the picture element data at a farther position, and therefore, the picture quality after the interpolation is lowered and the scale of the circuit is increased.
The present invention is made in view of such points, and an object thereof is to provide a picture signal recording and reproducing apparatus by which the adjacent normal picture elements can be reproduced even when there is a wrong hard disc in write-in and read-out of a plurality of hard discs used as a video server.
The picture signal recording and reproducing apparatus of the present invention is a picture signal recording and reproducing apparatus having a plurality of recording media and a write-in and read-out control means for controlling writing-in and reading-out of the picture signal data for the plurality of recording media, which comprises a picture element control means which records the adjacent picture element data of the picture signal data in different recording media respectively when writing the picture signal data in the plurality of recording media by the write-in and read-out control means. Furthermore, in the picture signal recording and reproducing apparatus of the present invention, the picture element control means is to return the picture element data of the picture signal data to the adjacent picture element data when reading out the picture signal data recorded in the plurality of recording media by the write-in and read-out control means.
Moreover, the picture signal recording and reproducing apparatus of the present invention is a picture signal recording and reproducing apparatus having a plurality of recording and reproducing units each being independently driven, which comprises: a striping means for striping a bit stream of a supplied picture signal for every picture element unit; and a record control means for assigning the picture element data striped by the striping means to the plurality of recording and reproducing units so that the adjacent picture element data in the horizontal direction and in the vertical direction of the picture signal may be recorded in different recording and reproducing unit respectively.
Furthermore, the picture signal recording and reproducing method of the present invention is a picture signal recording and reproducing method which records a picture signal into a plurality of recording and reproducing units each being independently driven, and which reproduces the picture signal from the plurality of recording and reproducing units, wherein a bit stream of a supplied picture signal is striped at every picture element unit, and wherein the striped picture element data are assigned to the plurality of recording and reproducing units respectively so that the adjacent picture element data in the horizontal direction and in the vertical direction of the picture signal may be recorded in different recording and reproducing units respectively.
According to the picture signal recording and reproducing apparatus of the present invention, the following actions are performed.
First, the write-in action will be described. When a write-in request is made, a command and picture signal data are supplied to the picture element control means.
In the picture element control means, a dummy picture element is inserted into the effective picture element. That is, in the picture element control means, the effective picture element in the horizontal direction of the picture signal data is extracted at every scanning line. Specifically, the picture element at the left end of the scanning line 1 as a start picture element of the picture frame is detected. From the detected start picture element, the number of effective picture elements in the horizontal direction previously determined in the range of the effective picture element is counted on the basis of a horizontal scanning clock, and if the counted value coincides with the preset value, the count is finished and a coincidence signal is outputted. By the coincidence signal, the dummy picture element is inserted in the range of the effective picture element in the horizontal direction of the scanning line 1.
When the dummy picture element is inserted, the vertical scanning clock 1 is counted from the output signal thereof, and since the value does not coincide with the number of the last scanning line, a discordance signal is outputted. By the discordance signal, the picture element at the left end of the scanning line 2 as the next start picture element is detected. From the detected start picture element, the number of effective picture elements is extracted, and the dummy picture element is inserted in the range of the effective picture element in the horizontal direction of the scanning line 2.
When the dummy picture element is inserted, a vertical scanning clock 2 is counted from the output signal, and since the value does not coincide with the number of the last scanning line, a discordance signal is outputted. By the discordance signal, the picture element at the left end of the scanning line 3 as the next start picture element is detected. From the detected start picture element, the number of effective picture elements is extracted, and the dummy picture element is inserted in the range of the effective picture element in the horizontal direction of the scanning line 3.
After that, continuing the repetition, the first vertical scanning clock from the last is counted, and since the value does not coincide with the number of the last scanning line, a discordance signal is outputted. By the discordance signal, the picture element at the left end of the last scanning line as the next start picture element is detected. From the detected start picture element, the effective picture element is extracted, and the dummy picture element is inserted in the range of the effective picture element in the horizontal direction of the last scanning line.
When the dummy picture element is inserted, the last vertical scanning clock is counted from the output signal, and since the value coincides with the number of the last scanning line, a coincidence signal is outputted. By the coincidence signal, the action in this frame is finished. After that, the action moves to the action of the next frame. Thus, the insertion action of the dummy picture element of each frame is performed in order.
The picture element data of the picture signal into which the dummy picture element is inserted, is supplied to the write-in and read-out control means.
By the write-in and read-out control means, the write-in action is started, and the bit stream of the picture signal is striped at every picture element unit, and the write-in action is performed to a plurality of recording means so that the adjacent picture element data in the vertical direction may be dispersedly accumulated in different recording means respectively.
The action to record the picture element data of the picture signal data into which the dummy picture element is inserted, in the recording means, will be described. Since the dummy picture element is inserted into the effective picture element in the horizontal direction of the picture signal data, different picture element data can be arranged in the vertical direction of the picture signal data, so that it does not occur that all upper and lower picture element data may become in error even when either of the plurality of recording means breaks down.
Next, the action of read-out will be described. When a read-out request is made, a command is supplied to the write-in and read-out control means. By the write-in and read-out control means, the read-out action is started, and the read-out action of the picture element data dispersedly accumulated in a plurality of recording means is performed. The read out divided data are composed to the original data. The composed data are supplied to the picture element control means.
At the picture element control means, the dummy picture element is deleted for the effective picture element. That is, in the picture element control means, the effective picture element in the horizontal direction of the picture signal data is extracted for every scanning line. Specifically, the picture element at the left end of the scanning line 1 as a start picture element of the picture frame, is detected. From the detected start picture element, the number of effective picture elements in the horizontal direction previously determined in the range of the effective picture element is counted on the basis of the horizontal scanning clock, and if the counted value coincides with the preset value, the count is finished and a coincidence signal is outputted. By the coincidence signal, an auxiliary signal data such as a header signal with a synchronization signal or the like relating to the transmission are added to the effective picture element data. In the effective picture element data to which the auxiliary signal data are added, the dummy picture element shown in the range of the record picture element is deleted for the range of the effective picture element in the horizontal direction of the scanning line 1.
When the dummy picture element is deleted, the vertical scanning clock 1 is counted from the output signal thereof, and since the value does not coincide with the number of the last scanning line, a discordance signal is outputted. By the discordance signal, the picture element at the left end of the scanning line 2 as the next start picture element is detected. From the detected start picture element, the horizontal scanning clock is counted, and if the counted value coincides with the preset value, the count is finished and a coincidence signal is outputted. By the coincidence signal, an auxiliary signal data such as a header signal with a synchronization signal or the like relating to the transmission are added to the effective picture element data. In the effective picture element data to which the auxiliary signal data are added, the dummy picture element shown in the range of the record picture element is deleted for the range of the effective picture element in the horizontal direction of the scanning line 2.
When the dummy picture element is deleted, the vertical scanning clock 2 is counted from the output signal thereof, and since the value does not coincide with the number of the last scanning line, a discordance signal is outputted. By the discordance signal, the picture element at the left end of the scanning line 3 as the next start picture element is detected. From the detected start picture element, the horizontal scanning clock is counted, and if the counted value coincides with the preset value, the count is finished and a coincidence signal is outputted. By the coincidence signal, the auxiliary signal data such as a header signal with a synchronization signal or the like relating to the transmission are added to the effective picture element data. In the effective picture element data to which the auxiliary signal data are added, the dummy picture element shown in the range of the record picture element is deleted for the range of the effective picture element in the horizontal direction of the scanning line 3.
After that, continuing the repetition, the first vertical scanning clock from the last scanning line is counted, and since the value does not coincide with the number of the last scanning line, a discordance signal is outputted. By the discordance signal, the picture element at the left end of the last scanning line as the next start picture element is detected. From the detected start picture element, the horizontal scanning clock is counted, and if the counted value coincides with the preset value, the count is finished and a coincidence signal is outputted. By the coincidence signal, the auxiliary signal data such as a header signal with a synchronization signal or the like relating to the transmission are added to the effective picture element data. In the effective picture element data to which the auxiliary signal data are added, the dummy picture element is deleted to the range of the effective picture element in the horizontal direction of the last scanning line.
When the dummy picture element is deleted, the last vertical scanning clock is counted from the output signal thereof, and since the value coincides with the number of the last scanning line, the count is finished if the counted value coincides with the preset value, and a coincidence signal is outputted. By the coincidence signal, the action in this frame is finished. After that, the action moves to the action of the next frame. Thus, the action of deletion of the dummy picture element from each frame is performed in order.
The interpolation processing of the picture element where an error flag is set up, of the picture element data in which the action of deletion of the dummy picture element has been performed, is performed. The interpolation processing is performed, as for the picture element of each point on the picture frame, by referring to the value of the picture element in the vicinity of the point thereof, on the basis of the ideal direction found by a calculation and the error flag of the picture element of each point.
First, the possibility of interpolation and replacement is judged from error flags of 8 points around an object picture element and the ideal direction found by the calculation of 1 direction among the horizontal direction, the vertical direction, the diagonally up to the left direction, and the diagonally up to the right direction. Specifically, whether the error flag of the object picture element is set up or not, is judged. If the error flag of the object picture element is not set up, the data is passed through. If the error flag of the object picture element is set up, whether the interpolation is possible or not, is judged. If the interpolation is possible, whether the interpolation is possible in the ideal direction or not, is judged. If the interpolation is not possible in the ideal direction, whether the interpolation is possible in another direction or not, is judged. The order of priority in determining another direction is the order of the horizontal direction, the vertical direction, the diagonally up to the left direction, and the diagonally up to the right direction.
Next, if the replacement is possible, whether the replacement is possible in the ideal direction or not, is judged. If the replacement is not possible in the ideal direction, whether the replacement is possible in another direction or not, is judged. The order of priority in determining another direction is the order of the horizontal direction, the vertical direction, the diagonally up to the left direction, and the diagonally up to the right direction.
Thus, whether the interpolation or the replacement is possible or not, is judged, and whether the interpolation or the replacement is possible in the ideal direction or in another direction or not, is judged.
Then, if it is judged that the interpolation is possible in the vertical direction, interpolation processing is performed. In the interpolation processing, an interpolation is performed between 2 points in the vertical direction when both the upper and lower 2 points in the vertical direction of the object picture element have no error flag set up. Furthermore, if it is judged that the replacement is possible in the diagonally up to the left direction, replacement processing is performed. In the replacement processing, a replacement is performed simply by either of the upper and lower 2 points in the diagonally up to the left direction of the object picture element, when the either has no error flag set up.
Thus, interpolation and replacement are performed according to error flags of 8 points around the object picture element and the ideal direction found by the calculation of 1 direction among the horizontal direction, the vertical direction, the diagonally up to the left direction, and the diagonally up to the right direction. Accordingly, even if either of the plurality of recording means breaks down, since different picture element data in the up and down direction are read out, the possibility that error flags may be set up at all of some picture element data, is low in interpolation or replacement processing of the picture element data, and therefore, the possibility that error flags of 8 points around the object picture element may be set up, is low, so that the interpolation or replacement processing can be performed by using the picture element of a point adjacent to the object picture element.
The picture signal data subjected to the interpolation processing or the replacement processing are transmitted. Thus, the read-out of the material of a series of programs or the like comes to an end.
Thus, by inserting a redundant picture element at the end of each scanning line, the adjacent picture elements between each scanning line can be recorded in different recording means, and therefore, even if a recording means breaks down, the probability that the normal adjacent picture elements may be reproduced, is high, so that the interpolation of the picture by using the adjacent picture elements may become easy.